Onan 6GO-F User Manual

MAINTENANCE AND REPAIR
CONNECTING RDDS.- The connecting rod lower end bearings are steel backed
and readiJ.y replaceable. When removing the connecting rods, be sUre to
note the numbers on the rods and bearing caps, and reassemble with the
numbers toward the camshaft. CQnnecting rods 1 and 3 are not inter-
changeable with rods 2 and, 4, nor are the bearings. Notches machined in
the connecting rod halves act as retainers for matching ears stamped
into the steel back of the bearing shells, or inserts. This design
locks the shells and prevents their turning in the rod. If a shell be-
. comes worn, both shells for that rod should be discarded, and new ones
installed. The shells are designed to give a clearance of .0015" to
.002" without any scraping or other fitting. Under no condition should
fitting ever be attempted by scraping or filing of the cap or upper half
of the rod, as this would permanently ruin the rod. Be sure. that rods
and caps, as well as bearing shells are perfectly clean and free of oil
when inserting the· shells. Qil on the back of the shell will prevent
proper sea.ting of the shell in the rod or cap. Oil the crankshaft jour-
nal atter the bearing shell has been firmly seated.
The sides of the connecting rod crank ends are not babbitt lined in this
engine. The .faces are steel and, being exposed to the steel crankshaft,
it is of vital importance that the side play clearance of .006" to .010"
be maintained. When installing new pistons, pins, or connecting rods,
be sure pistons and connecting rod assemblies are first properly aligned
on an accurate aligning gauge.
MAIN. BEARINGS.- The crankshaft main bearings are of the same type as the
connecting rod bearings. The upper and lower shells are made in pairs
for each individual bearing, but front, eenter and rear bearings .are not
interchangeable as pairs. The same general directions given for fitting
the connecting rod bearings should be observed in fitting the main bear-
ings. The clearance, when installed, should be .0015" tl> .002". The
rear face of the front main bearing takes the end thrust of the crank-
shaft. The crankshaft end play should be .004" te .006
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and is regula-
ted by a removable thrust collar just to the rear of the crankshaft gear ,
together with lit. shim pack to the rear Qf this collar. When servicing the
crankshaft or any parts in connection with the shaft, especially connect-
ing rod and main bearings, alwRY.s be sure that all oil holes in the shaft
are open and clean. Note that one center main bearing cap s.crew is short-
er then the other bearing cap screws. This shorter screw must be instal-
led on the camshaft side of the bearing cap. Use of one of the longer
screws at this point will block the oil passage.
PISTON PINS.- The hardened piston pins are selected in production to ob-
tain a 0.0003" .. 100se fit in connecting rod pin bushing, and llght push
fit in piston boss. By heating the piston in hot water. the piston pin
can be pushed in by hand. Maintain these clearances if necessary to fit
oversize piston pins. Pins are available in .003", .005", and .010" over-
sizes. When reinstalling old pistons. be sure that they are installed in
their original cylinder, and in the same position relative to the numbered
side of the connecting .rod. When reassembling. make sure that the snap
ring at either end of the pin is tightly in place.
CAMSHAFT.- The camshaft is an alloy steel forging. Provided that proper
lubrication is supplied, the camshaft and its bearings should never re-
quire servicing. The €:8IIlB, if cut by too close adjustment of the tappet
clearance. can be recond:1tioRed by careful honing if not too badly damaged.
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Onan 6GO-F Specifications

General

Brand	Onan
Model	6GO-F
Category	Inverter
Language	English